Only Sulphur-free diesel to be used with a certain engine oil?

halfbytecode

Well-known member
Joined
Oct 7, 2017
Location
S
TDI
1.6 TDI - CR, 2010 Polo Sedan
Hi,

I am currently using Liqui Moly Top-Tec 4100 5W-40 in my car. It says in the Additional Information in the webpage linked below, to only use it with Sulphur-free diesel.

https://products.liqui-moly.com/top-tec-4100-5w-40-3.html

Searching around made it seem that it could mean diesel with sulphur content less than 10 ppm (Euro-6 complaint).

However, we have Euro-4 complaint diesel with less than 50 ppm around here mostly.

• Could someone please explain the reason for recommending usage of only sulphur-free diesel with this engine oil?

• Is this likely to be an issue for me?
 

CleverUserName

Veteran Member
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Oct 25, 2014
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NorCal
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2014 OZ Cruze CTD & 2010 JSW 6MT & 2017 GMC Canyon CCLB ATX 2.8 Duramax
Hi,

I am currently using Liqui Moly Top-Tec 4100 5W-40 in my car. It says in the Additional Information in the webpage linked below, to only use it with Sulphur-free diesel.

https://products.liqui-moly.com/top-tec-4100-5w-40-3.html

Searching around made it seem that it could mean diesel with sulphur content less than 10 ppm (Euro-6 complaint).

However, we have Euro-4 complaint diesel with less than 50 ppm around here mostly.

• Could someone please explain the reason for recommending usage of only sulphur-free diesel with this engine oil?

• Is this likely to be an issue for me?
Fuel quality and Sulfur content directly effects the oil life and interval.

Sulfur, nitric acid and other combustion by-products will deplete the buffering qualities of engine oil. Eventually it may become acidic and cause internal corrosion inside your engine.
 

scooperhsd

Top Post Dawg
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Aug 19, 2003
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Kansas City KS
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NB, 2000, RED(5 Speed conversion) 2015 Golf SE
In North America, the spec for onroad diesel is called ULSD (aka Ultra Low Sulfur Diesel). The spec is for 15ppm sulfur, but it is fairly common to find it at 10 ppm sulfur.
 

halfbytecode

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Joined
Oct 7, 2017
Location
S
TDI
1.6 TDI - CR, 2010 Polo Sedan
Fuel quality and Sulfur content directly effects the oil life and interval.



Sulfur, nitric acid and other combustion by-products will deplete the buffering qualities of engine oil. Eventually it may become acidic and cause internal corrosion inside your engine.
I find it strange they don't mention this low sulphur diesel fuel requirement on the product packaging, and yet they sell the product here.

They also seem to have it in the spec sheet that the product is compliant with Euro-4 emission requirements.

This is a bit strange and contradictory with the sulphur-free diesel usage requirement.
 
Last edited:

halfbytecode

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Joined
Oct 7, 2017
Location
S
TDI
1.6 TDI - CR, 2010 Polo Sedan
In North America, the spec for onroad diesel is called ULSD (aka Ultra Low Sulfur Diesel). The spec is for 15ppm sulfur, but it is fairly common to find it at 10 ppm sulfur.
Yes I read the terms ULSD and sulphur-free diesel being used interchangeably.
 

Powder Hound

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Actually, the low sulfur requirements for apply to any diesel equipped with a catalyst here is the USofA. Other countries will have the same requirements depending on their outlook on trying for breathable exhaust. The oil should be low/no sulfur as well, hence the switch to zinc based anti-wear additives (ZDDP) vs. the molybdenum (MoS2) based additive that was used.

Also, it explains why gear oils still contain the moly antiwear: they don't go through a catalyst.

Cheers,

PH
 

halfbytecode

Well-known member
Joined
Oct 7, 2017
Location
S
TDI
1.6 TDI - CR, 2010 Polo Sedan
Actually, the low sulfur requirements for apply to any diesel equipped with a catalyst here is the USofA. Other countries will have the same requirements depending on their outlook on trying for breathable exhaust. The oil should be low/no sulfur as well, hence the switch to zinc based anti-wear additives (ZDDP) vs. the molybdenum (MoS2) based additive that was used.



Also, it explains why gear oils still contain the moly antiwear: they don't go through a catalyst.



Cheers,



PH
My car is not equipped with DPF. I am still trying to wrap my head around the fact they sell this oil here, without the low sulphur diesel usage warning on the packaging!

I only found about that in the technical specifications.
 

IndigoBlueWagon

TDIClub Enthusiast, Principal IDParts, Vendor , w/
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Aug 16, 2004
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South of Boston
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'97 Passat, '99.5 Golf, '02 Jetta Wagon, '15 GSW
I don't know where "S" is, but do you have high sulfur diesel available? In the US all over the road diesel has been ULSD for the past 12 years.
 

halfbytecode

Well-known member
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Oct 7, 2017
Location
S
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1.6 TDI - CR, 2010 Polo Sedan
I don't know where "S" is, but do you have high sulfur diesel available? In the US all over the road diesel has been ULSD for the past 12 years.
We have diesel with 50 ppm of sulphur. ULSD (15 ppm) is not usually available here.

Is 50 ppm of sulphur considered high?
 

IndigoBlueWagon

TDIClub Enthusiast, Principal IDParts, Vendor , w/
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Aug 16, 2004
Location
South of Boston
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'97 Passat, '99.5 Golf, '02 Jetta Wagon, '15 GSW
I don't think so. Before ULSD our diesel had 500 PPM sulfur. Pre-1993 it had 5,000 PPM.

I don't think you'd have any trouble with that oil and 50 PPM diesel. If you're concerned about it you could shorten the change interval a bit.
 
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